1. Field of the Invention
This invention relates to a half bearing constituting a cylindrical plain bearing when two of the half bearings are combined together.
2. Description of the Related Art
A plain bearing is used to support a rotating shaft such as a crankshaft of an internal combustion engine, for example. The plain bearing is made by combining two generally semicylindrical half bearings into a cylindrical form. A lubricating oil is supplied between an inner circumferential surface of the plain bearing and the rotating shaft so as to form an oil film.
Conventional half bearings constituting the plain bearing have crush relief surfaces formed on inner circumferential surfaces of both circumferential ends thereof respectively. The crush relief surfaces are formed so as to spread substantially over an entire width of the bearing or axial dimension of the bearing with respect to a shaft supported by the bearing. When a plain bearing is assembled into a bearing housing, joints of the respective half bearings sometimes shift from each other. Furthermore, when a crush height of the bearing is excessively high, the bearing is sometimes brought into a local contact with the shaft as the result of a radially inward swelling due to deformation in the vicinity of the joint. The aforesaid crush relief surfaces prevent the shift of the joints and the local contact. In the conventional half bearings, however, a large amount of lubricating oil leaks axially from each crush relief surface.